17.canvas绘制圆弧.html

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>画布控制</title>
	<style type="text/css">
		*{
			padding: 0;
			margin: 0;
		}
		canvas{
			display: block;
			background: #ccc;
			margin: 50px auto;
		}
	</style>
</head>
<body>
	<canvas id="canvas" height="500" width="800"></canvas>
	<script type="text/javascript">
		window.onload = function(){
			var canvas = document.getElementById("canvas");
			var cv = canvas.getContext('2d');

		
			cv.strokeStyle = "red";
			cv.lineWidth = "5";
			//画圆弧
			cv.arc(300,300,150,0,150*Math.PI/180);//参数分别是距离左边，距离上边，半径，起始弧度，终止弧度。
			cv.stroke();//绘制路径

			//填充
			cv.fillStyle = "green";
			cv.fill();
		}
	</script>
</body>
</html>